ロボットアーム支援による一次股関節全置換術における入院期間の短縮と3.5年追跡での生存率の差なし：傾向スコアマッチングを用いた前向きコホート研究

Although robotic arm-assisted total hip arthroplasty (RA-THA) has been increasing in popularity, the outcomes following its use are still uncertain.

We performed a propensity-matched prospective cohort study comparing all-cause revision, odds of instability/dislocation, odds of periprosthetic joint infection (PJI), and hospital length of stay (HLOS) between patients receiving an RA-THA versus a conventional total hip arthroplasty (CO-THA). Consecutive patients undergoing a primary elective total hip arthroplasty (THA) via a posterior approach at our institution between January 2019 and February 2024 were included. Those who received a bilateral simultaneous THA were excluded. We successfully matched 268 pairs of hips.

There was no difference in all-cause revision risk between the RA-THA and CO-THA groups (hazard ratio = 1.00, P = 1.000). Furthermore, there was also no significant difference in the odds of instability/dislocation (odds ratio = 1.00, P = 1.000) and the odds of PJI (odds ratio = 0.75, P = 0.704. The HLOS was significantly shorter in the RA-THA cohort by 0.49 days (P = 0.044). The median follow-up duration was 3.46 years (interquartile range: 1.92 to 4.64).

Although there was no difference in short-term revision risk in patients receiving an RA-THA versus a CO-THA, likely, the benefits from improved implant positioning are yet to be realized. This study is underpowered, and results should be interpreted with caution. The shorter HLOS observed in the RA-THA group may help offset the increase in consumable costs incurred. Further studies with long-term follow-up, alongside a cost-effectiveness analysis, are required.